The present invention relates to a demountable subassembly for units for compacting bundles of textile fibres.
The field of application of the present invention is that of spinning machines provided with a plurality of adjacent spinning stations, in each of which there is a drawing unit associated with a compacting unit, for transforming a roving or bundle of textile fibres into a twisted yarn.
Each drawing unit usually comprises three pairs of members which draw the roving along at increasing linear velocities in order to attenuate it gradually.
The roving output by the drawing unit then goes to a compacting unit disposed downstream of the drawing unit, before being sent for twisting.
Each compacting unit is served by a fixed tube which is common to several spinning stations disposed side by side and is connected to a suction source; the tube has a narrow suction slot arranged on the path of the roving and along its direction of advance, in each station.
A filter loop of flexible textile material which covers the corresponding slot with a wide margin is circulated about the fixed tube by a pressure roller of elastomeric material which presses the roving against the filter loop. The path of each filter loop is defined by a portion of the surface of the tube and by a guide element with a resilient element for keeping the filter loop tensioned.
A main object of the present invention is to propose a subassembly for a compacting unit of the type discussed above in which the various elements which make up the subassembly can be assembled and disassembled easily and conveniently to facilitate both the assembly of the unit and supplementary maintenance operations.
A particular object of the invention is to facilitate the periodic cleaning of these members to prevent the formation of deposits of dust and of fibrous material which are present in large quantities in the working environment and may adversely affect the operation and the performance of spinning machines, in particular, blocking the various suction openings or obstructing the movement of the movable parts.
Another object of the invention is to reduce or at least not to promote the deposition of dust and textile fibres on the compacting unit.
These and other objects and advantages which will be understood further from the following are achieved, according to the present invention, by a subassembly having the characteristics defined in the appended claims.